It is no secret for anyone that Intel engineers tried to design not only fast CPUs but also highly economical CPUs when they were working on the new Core microarchitecture. Therefore, they started active promotion of the “performance-per-watt’ concept long before the processor launch and they expect it to turn into the major criterion for processor consumer qualities evaluation very soon. That is why it is extremely interesting to look into the practical power consumption of the new processors and compare it to that of the previous-generation CPUs based on older microarchitecture.
As always, we used a special S&M utility to measure the maximum power consumption (you can download this utility here). We measured the current that goes through the CPU power circuitry. So, the numbers given below do not take into account the efficiency of the CPU voltage regulator laid out on the mainboard.
First of all, we measured the processors power consumption in idle mode. Cool’n’Quiet and Intel Enhanced SpeedStep power saving technologies were disabled in this test.
The results are very diverse, as you can see, which is probably caused by too different processor models participating. However, generally speaking, Core 2 Duo processors can really boast the most economical performance in idle mode.
Now let’s take a look at much more interesting results obtained when our CPUs were loaded to the full extent.
Core 2 Duo and Core 2 Extreme processors impressed us with their low level of power consumption. These processors are truly ahead of their competitors from the power consumption standpoint. The top Core 2 Extreme X6800 with the clock speed of 2.93GHz consumes even less power than Pentium D 915 and Athlon 64 X2 3800+. And if we compare the power consumption of this CPU with that of the same type processors such as Athlon 64 FX-62 or Pentium Extreme Edition 965, then the difference will be almost twofold.
In other words, Intel processors on Core microarchitecture are not only unprecedentedly fast but also impressively economical. So far they have no real competitors here. However, we have to stress that we haven’t yet finished testing the Energy Efficient AMD processors that are about to start selling fairly soon. Hopefully, they will get close to Core 2 Duo solutions from the power consumption standpoint.